whatever someone is willing to pay for it.
if you are selling, usually not as much as you think, if you are buying, more than you would like to pay.
bantys don't bring the money a large fowl do.
is it of good quality?
male or female?
I think a couple bucks is about right.
if you really want to know, take it to your local livestock auction, if they do poultry. whatever it brings will be it's value, on that day, in that market.
good luck.